People used to write websites and web apps long before Angular and single page apps came about. I remember a big part of the beginning of my career it was perfectly standard to render HTML server side. All the templating would be done server side and you'd serve dynamic HTML to browser. With usually some small JavaScripts in HTML for client side.
Even today not everybody uses SPAs. Lots of big old school websites generated dynamically on server. Many Django and Rails projects built that way. Also lots of legacy Java stuff and PHP websites (all Wordpress and Drupal sites out there for example, and there are millions).
LOL, where to start? 1) There is such a thing as a web app which doesn't run Javascript. 2) Rails can generate and serve JS. 3) Rails was the first web framework with AJAX integration back in 2004 via PrototypeJS, this is the library that kicked off the entire movement that gave us the modern JS world we have today.
Even today not everybody uses SPAs. Lots of big old school websites generated dynamically on server. Many Django and Rails projects built that way. Also lots of legacy Java stuff and PHP websites (all Wordpress and Drupal sites out there for example, and there are millions).